Polynucleotides and methods for the improvement of plants

ABSTRACT

The invention provides methods for producing a plant with altered seed yield, the methods comprising transformation of a plant with a genetic construct including a polynucleotide encoding of a polypeptide with the amino acid sequence of SEQ ID NO: 1 or a variant or fragment thereof. The method also provides isolated polypeptides, polynucleotides, constructs and vectors useful for producing a plant with altered seed yield. The method also provides plant cell and plants transformed to contain and express the polypeptides, polynucleotides and constructs. The invention also provides plants produced by methods of the invention.

TECHNICAL FIELD

The present invention relates to compositions and methods for producing plants with increased seed yield.

BACKGROUND ART

As the population of the world increases, a major goal of agricultural research is to improve the grain yield of crop plant species.

Such improvements have until recently depended on selective breeding of plants for desirable characteristics. However for many plants the heterogeneous genetic compliments produced in off-spring do not result in the same desirable traits as those of their parents, thus limiting the effectiveness of selective breeding approaches.

Advances in molecular biology now make it possible to genetically manipulate the germplasm of both plants and animals. Genetic engineering of plants involves the isolation and manipulation of genetic material and the subsequent introduction of such material into a plant. This technology has led to the development of plants that are capable of expressing pharmaceuticals and other chemicals, plants with increased pest resistance, increased stress tolerance, and plants that express other beneficial traits.

Improvements in the grain yield of plant crop plants may be achieved by developing plants that produce more seed or grain than the equivalent wild-type plants.

Thus, there exists a need for plants with increased seed yield relative to their normally cultivated counterparts.

It is an object of the invention to provide improved compositions and/or methods for developing plant varieties with improved seed or grain seed yield or at least to provide the public with a useful choice.

SUMMARY OF THE INVENTION

In a first aspect the invention provides a method for producing a plant with altered seed yield, the method comprising transformation of a plant with:

-   -   a) a polynucleotide encoding of a polypeptide with the amino         acid sequence of SEQ ID. NO:1 or a variant of the polypeptide,         wherein the variant is capable of modulating seed yield in a         plant;     -   b) a polynucleotide comprising a fragment, of at least 15         nucleotides in length, of the polynucleotide of a), or     -   c) a polynucleotide comprising a compliment, of at least 15         nucleotides in length, of the polynucleotide of a).

In one embodiment the variant has at least 70% sequence identity to a polypeptide with the amino acid sequence of SEQ ID NO: 1.

Preferably the variant is derived from a plant species and comprises the sequence of SEQ ID NO: 32.

In one embodiment the variant is from a monocotyledonous species and comprises the sequence of SEQ ID NO: 33.

In a preferred embodiment the variant comprises an amino acid sequence selected from any one of SEQ ID NO: 2-31.

In a preferred embodiment the polypeptide or variant is a glutamate decarboxylase.

In a preferred embodiment the polynucleotide of a) encodes a polypeptide with the amino acid sequence of SEQ ID NO: 1.

In a preferred embodiment the plant is transformed with a genetic construct containing the polynucleotide.

In a further aspect the invention provides a method of producing a plant with altered seed yield, the method comprising transformation of a plant cell or plant with:

-   -   a) a polynucleotide comprising the nucleotide sequence of SEQ ID         NO: 34, or a variant thereof, wherein the variant encodes a         polypeptide capable of modulating seed yield in a plant;     -   b) a polynucleotide comprising a fragment, of at least 15         nucleotides in length, of the polynucleotide of a), or     -   c) a polynucleotide comprising a complement, of at least 15         nucleotides in length, of the polynucleotide of a).

In a one embodiment the variant comprises the sequence of any one of SEQ ID NO: 35 to 65.

In a preferred embodiment the polynucleotide or variant in a) encodes a polypeptide which is a glutamate decarboxylase.

In a further embodiment the polynucleotide of a) comprises the sequence of SEQ ID NO: 34.

In a further embodiment the polynucleotide of a) comprises the coding sequence of SEQ ID NO: 34.

In a preferred embodiment the plant is transformed with a genetic construct containing the polynucleotide.

Preferably the plant produced by the method of the invention has increased seed yield relative to a suitable control plant.

In a further embodiment the method for producing a plant with altered seed yield comprises transformation of a plant cell, or plant with a genetic construct capable or altering expression of a polypeptide which modulates seed yield.

In one embodiment, the method results in a plant with decreased seed yield, relative to a suitable control, due to transformation of a plant cell or plant, with a genetic construct capable of down-regulating expression of a polypeptide which positively modulates seed yield.

In a preferred embodiment, the method results in a plant with increased seed yield, relative to a suitable control, due to transformation of a plant cell or plant, with a genetic construct capable of up-regulating expression of a polypeptide which positively modulates seed yield.

In a further aspect the invention provides a plant cell or plant produced by a method of the invention.

Preferably the plant produced by the method of the invention has increased seed yield relative to a suitable control plant.

In a further aspect the invention provides an isolated polynucleotide having at least 75% sequence identity to a nucleotide sequence that encodes a polypeptide comprising an amino acid sequence selected of SEQ ID NO: 1, wherein the polynucleotide encodes a polypeptide capable of modulating seed yield in a plant.

In one embodiment said nucleotide sequence comprises the sequence of SEQ ID NO: 34.

In a further embodiment said nucleotide sequence comprises the full-length coding sequence of SEQ ID NO:34.

In a further aspect the invention provides a polynucleotide encoding a polypeptide with at least 70% identity to the amino acid sequence of SEQ ID NO: 1.

Preferably the polypeptide is capable of modulating seed yield in a plant.

Preferably the polypeptide is a glutamate decarboxylase.

In a further aspect the invention provides an isolated polynucleotide that encodes a polypeptide comprising an amino acid sequence SEQ ID NO: 1.

In a further embodiment the polynucleotide comprises the sequence of SEQ ID NO: 34.

In a further embodiment the polynucleotide comprises the full-length coding sequence of SEQ ID NO: 34.

In a further aspect the invention provides an isolated polynucleotide comprising the sequence of SEQ ID NO: 34 or a variant thereof, wherein the variant is from ryegrass or fescue, and encodes a polypeptide capable of modulating seed yield in a plant.

In one embodiment the polypeptide is a glutamate decarboxylase.

In one embodiment the isolated polynucleotide comprises the sequence of SEQ ID NO: 34.

In a further aspect the invention provides an isolated polypeptide having at least 83% sequence identity to the amino acid sequence of SEQ ID NO: 1, wherein the polypeptide is capable of modulating seed yield in a plant.

In one embodiment the isolated polypeptide of comprises the amino acid sequence of SEQ ID NO: 1.

In a further aspect the invention provides an isolated polynucleotide encoding a polypeptide of the invention.

In a further aspect the invention provides an isolated polynucleotide comprising:

-   -   a) a polynucleotide comprising a fragment, of at least 15         nucleotides in length, of a polynucleotide of the invention;     -   b) a polynucleotide comprising a complement, of at least 15         nucleotides in length, of the polynucleotide of the invention;         or     -   c) a polynucleotide comprising a sequence, of at least 15         nucleotides in length, capable of hybridising to the         polynucleotide of the invention.

In a further aspect the invention provides a genetic construct which comprises a polynucleotide of the invention.

In one embodiment the genetic construct is an expression construct.

In one embodiment the construct comprises a promoter operably linked to the polynucleotide.

In a further embodiment the construct comprises a terminator operably linked to the polynucleotide.

Preferably the promoter, the terminator, or both is/are derived from a different source than the polynucleotide.

In one embodiment the different source is a different species:

In a further aspect the invention provides a vector comprising a genetic construct or expression construct of the invention.

In a further aspect the invention provides a host cell genetically modified, to express a polynucleotide of the invention, or a polypeptide of the invention.

In a further aspect the invention provides a host cell comprising a genetic construct or expression construct of the invention.

In a further aspect the invention provides a plant cell genetically modified to express a polynucleotide of the invention, or a polypeptide of the invention.

In a further aspect the invention provides a plant cell which comprises a genetic construct of the invention or the expression construct of the invention.

In a further aspect the invention provides a plant which comprises a plant cell of the invention.

In a further aspect the invention provides a method for selecting a plant with altered seed yield relative to suitable contrast, the method comprising testing of a plant for altered expression of a polynucleotide of the invention.

In a further aspect the invention provides a method for selecting a plant with altered seed yield relative to a suitable control, the method comprising testing of a plant for altered expression of a polypeptide of the invention.

In a further aspect the invention provides a plant cell or plant produced by the method of the invention.

In a further aspect the invention provides a plant selected by the method of the invention.

In a further aspect the invention provides a population or group of plants selected by the method of the invention.

In a further aspect the invention provides an antibody raised against a polypeptide of the invention.

The polynucleotides and polynucleotide variants of the invention may be derived from any species and/or may be produced synthetically or recombinantly.

In one embodiment the polynucleotide or variant, is derived from a plant species.

In a further embodiment the polynucleotide or variant, is derived from a gymnosperm plant species.

In a further embodiment the polynucleotide or variant, is derived from an angiosperm plant species.

In a further embodiment the polynucleotide or variant, is derived from a from dicotyledonous plant species.

In a further embodiment the polynucleotide or variant, is derived from a monocotylenouous plant species.

The polypeptide and polypeptide variants, of the invention may be derived from any species and/or may be produced synthetically or recombinantly.

In one embodiment the polypeptide or variant, is derived from a plant species.

In a further embodiment the polypeptide or variant, is derived from a gymnosperm plant species.

In a further embodiment the polypeptide or variant, is derived from an angiosperm plant species.

In a further embodiment the polypeptide or variant, is derived from a from dicotyledonous plant species.

In a further embodiment the polypeptide or variant, is derived from a monocotylenouous plant species.

The plant cells and plants, of the invention may be derived from any species.

In one embodiment the plant cell or plant, is derived from a gymnosperm plant species.

In a further embodiment the plant cell or plant, is derived from an angiosperm plant species.

In a further embodiment the plant cell or plant, is derived from a from dicotyledonous plant species.

In a further embodiment the plant cell or plant, is derived from a monocotylenouous plant species.

Preferred dicotyledonous genera include: Amygdalus, Anacardium, Arachis, Brassica, Cajanus, Cannabis, Carthamus, Carya, Ceiba, Cicer, Cocos, Coriandrum, Coronilla, Cossypium, Crotalaria, Dolichos, Elaeis, lycine, Gossypium, Helianthus, Lathyrus, Lens, Lespedeza, Linum, Lotus, Lupinus, Macadamia, Medicago, Melilotus, Mucuna, Olea, Onobrychis, Ornithopus, Papaver, Phaseolus, Phoenix, Pistacia, Pisum, Prunus, Pueraria, Ribes, Ricinus, Sesamum, Theobroma, Trifolium, Trigonella, Vicia and Vigna.

Preferred dicotyledonous species include: Amygdalus communis, Anacardium occidentale, Arachis hypogaea, Arachis hypogea, Brassica napus Rape, Brassica nigra. Brassica campestris, Cajanus cajan, Cajanus indicus, Cannabis sativa, Carthamus tinctorius, Carya illinoinensis, Ceiba pentandra, Cicer arietinum, Cocos nucifera, Coriandrum sativum, Coronilla varia, Cossypium hirsutum, Crotalaria juncea, Dolichos lablab, Elaeis guineensis, Gossypium arboreum, Gossypium nanking, Gossypium barbadense, Gossypium herbaceum, Gossypium hirsutum, Glycine max, Glycine ussuriensis, Glycine gracilis, Helianthus annus, Lathyrus angustifolius, Lathyrus luteus, Lathyrus mutabilis, Lathyrus sericea, Lathyrus striata, Lathyrus uliginosus, Lathyrus sativus, Lens culinaris, Lespedeza stipulacea, Linum usitatissimum, Lotus corniculatus, Lupinus albus, Medicago arabica, Medicago arborea, Medicago falcate, Medicago hispida, Medicago officinalis, Medicago sativa, Medicago tribuloides, Macadamia integrifolia, Melilotus albus, Mucuna pruriens, Olea europaea, Onobrychis viciifolia, Ornithopus sativus, Phaseolus aureus, Phaseolus aureus cerasifera, Phaseolus aureus cerasus, Phaseolus aureus coccineus, Phaseolus aureus domestica, Phaseolus aureus lunatus, Phaseolus aureus maheleb, Phaseolus aureus mungo, Phaseolus aureus persica, Phaseolus aureus pseudocerasus, Phaseolus aureus vulgaris, Papaver somniferum, Phaseolus acutifolius, Phoenix dactylifera, Pistacia vera, Pisum sativum, Prunus amygdalus, Prunus armeniaca, Pueraria thunbergiana, Ribes nigrum, Ribes rubrum, Ribes grossularia, Ricinus communis, Sesamum indicum, Trifolium augustifolium, Trifolium diffusum, Trifolium hybridum, Trifolium incarnatum, Trifolium ingrescens, Trifolium pratense, Trifolium repens, Trifolium resupinatum, Trifolium subterraneum, Theobroma cacao, Trifolium alexandrinum, Trigonella foenumgraecum, Vigna angustifolia, Vigna atropurpurea, Vigna calcarata, Vigna dasycarpa, Vigna ervilia, Vigna oxycoccos, Vigna pannonica, Vigna sesquipedalis, Vigna sinensis, Vigna villosa, Vicia faba, Vicia sative and Vigna angularis.

Preferred monocotyledonous genera include: Agropyron, Allium, Alopecurus, Andropogon, Arrhenatherum, Asparagus, Avena, Bambusa, Bothrichloa, Bouteloua, Bromus, Cenchrus, Chloris, Cymbopogon, Cynodon, Dactylis, Dichanthium, Digitaria, Eleusine, Elymus, Eragrostis, Fagopyrum, Festuca, Hordeum, Lolium, Oryza, Panicum, Paspalum, Pennisetum, Phalaris, Phleum, Poa, Saccharum, Secale, Setaria, Sorghastrum, Sorghum, Triticum, Vanilla, x Triticosecale and Zea.

Preferred monocotyledonous species include: Agropyron desertorum, Agropyron elongatum, Agropyron spicatum, Agropyron trachycaulum, Agropyron trichophorum, Allium fistulosum, Allium sativum, Alopecurus pratensis, Andropogon gerardi, Arrhenatherum elatius, Asparagus officinalis, Avena sativa, Bambusa vulgaris, Bothrichloa barbinodis, Bothrichloa ischaemum, Bouteloua curipendula, Bouteloua gracilis, Bromus erectus, Cenchrus ciliaris, Chloris gayana, Cymbopogon nardus, Cynodon dactylon, Dactylis glomerata, Dichanthium annulatum, Digitaria decumbens, Eleusine coracan, Elymus angustus, Eragrostis curvula, Eragrostis tef, Fagopyrum esculentum, Fagopyrum tataricum, Festuca arundinacea, Hordeum distichum, Hordeum vulgare, Lolium perenne, Lolium multiflorum, Oryza sativa, Panicum italicium, Panicum maximum, Panicum miliaceum, Paspalum dilatatum, Pennisetum clandestinum, Pennisetum glaucum, Phalaris arundinacea, Phleum bertolinii, Poa fendleriana, Poa nemoralis, Saccharum robustum, Saccharum sinense, Secale cereale, Setaria sphacelata, Sorghastrum nutans, Sorghum dochna, Sorghum halepense, Sorghum bicolor, Triticum aestivum, Triticum dicoccum, X Triticosecale, Zea mays, Agropyron cristatum, Agropyron intermedium, Agropyron smithii, Allium ascalonicum, Allium cepa, Allium chinense, Allium porrum, Allium schoenoprasum, Avena nuda, Bambusa vulgaris, Bothrichloa saccharoides, Bouteloua eriopoda, Bromus inermis, Bromus riparius, Dactylis aristatum, Dactylis sericeum, Digitaria smutsii, Elymus junceus, Festuca ovina, Festuca pratensis, Festuca rubra, Panicum purpurascens, Panicum virgatum, Paspalum notatum, Pennisetum purpureum, Pennisetum spicatum, Phleum pratense, Poa pratensis, Saccharum officinarum, Saccharum spontaneum, Sorghum sudanense, Triticum durum, Triticum monococcum, Vanilla fragrans and Zea mays.

Preferred plants are from the genera Lolium and Trifolium. Particularly preferred are the species Lolium perenne and Trifolium repens.

Particularly preferred monocotyledonous plant species are: Lolium perenne and Oryza sativa.

The term “plant” is intended to include a whole plant, any part of a plant, propagules and progeny of a plant.

The term ‘propagule’ means any part of a plant that may be used in reproduction or propagation, either sexual or asexual, including seeds and cuttings.

DETAILED DESCRIPTION General Definitions

The term “comprising” as used in this specification means “consisting at least in part of”. When interpreting each statement in this specification that includes the term “comprising”, features other than that or those prefaced by the term may also be present. Related terms such as “comprise” and “comprises” are to be interpreted in the same manner.

In this specification where reference has been made to patent specifications, other external documents, or other sources of information, this is generally for the purpose of providing a context for discussing the features of the invention. Unless specifically stated otherwise, reference to such external documents is not to be construed as an admission that such documents, or such sources of information, in any jurisdiction, are prior art, or form part of the common general knowledge in the art.

Polynucleotides and Fragments

The term “polynucleotide(s),” as used herein, means a single or double-stranded deoxyribonucleotide or ribonucleotide polymer of any length but preferably at least 15 nucleotides, and include as non-limiting examples, coding and non-coding sequences of a gene, sense and antisense sequences complements, exons, introns, genomic DNA, cDNA, pre-mRNA, mRNA, rRNA, siRNA, miRNA, tRNA, ribozymes, recombinant polypeptides, isolated and purified naturally occurring DNA or RNA sequences, synthetic RNA and DNA sequences, nucleic acid probes, primers and fragments.

A “fragment” of a polynucleotide sequence provided herein is a subsequence of contiguous nucleotides that is capable of specific hybridization to a target of interest, e.g., a sequence that is at least 15 nucleotides in length. The fragments of the invention comprise 15 nucleotides, preferably at least 20 nucleotides, more preferably at least 30 nucleotides, more preferably at least 50 nucleotides, more preferably at least 50 nucleotides and most preferably at least 60 nucleotides of contiguous nucleotides of a polynucleotide of the invention. A fragment of a polynucleotide sequence can be used in antisense, gene silencing, triple helix or ribozyme technology, or as a primer, a probe, included in a microarray, or used in polynucleotide-based selection methods of the invention.

The term “primer” refers to a short polynucleotide, usually having a free 3′OH group, that is hybridized to a template and used for priming polymerization of a polynucleotide complementary to the target.

The term “probe” refers to a short polynucleotide that is used to detect a polynucleotide sequence, that is complementary to the probe, in a hybridization-based assay. The probe may consist of a “fragment” of a polynucleotide as defined herein.

Polypeptides and Fragments

The term “polypeptide”, as used herein, encompasses amino acid chains of any length but preferably at least 5 amino acids, including full-length proteins, in which amino acid residues are linked by covalent peptide bonds. Polypeptides of the present invention may be purified natural products, or may be produced partially or wholly using recombinant or synthetic techniques. The term may refer to a polypeptide, an aggregate of a polypeptide such as a dimer or other multimer, a fusion polypeptide, a polypeptide fragment, a polypeptide variant, or derivative thereof.

A “fragment” of a polypeptide is a subsequence of the polypeptide that performs a function that is required for the biological activity and/or provides three dimensional structure of the polypeptide. The term may refer to a polypeptide, an aggregate of a polypeptide such as a dimer or other multimer, a fusion polypeptide, a polypeptide fragment, a polypeptide variant, or derivative thereof capable of performing the above enzymatic activity.

The term “isolated” as applied to the polynucleotide or polypeptide sequences disclosed herein is used to refer to sequences that are removed from their natural cellular environment. An isolated molecule may be obtained by any method or combination of methods including biochemical, recombinant, and synthetic techniques.

The term “recombinant” refers to a polynucleotide sequence that is removed from sequences that surround it in its natural context and/or is recombined with sequences that are not present in its natural context.

A “recombinant” polypeptide sequence is produced by translation from a “recombinant” polynucleotide sequence.

The term “derived from” with respect to polynucleotides or polypeptides of the invention being derived from a particular genera or species, means that the polynucleotide or polypeptide has the same sequence as a polynucleotide or polypeptide found naturally in that genera or species. The polynucleotide or polypeptide, derived from a particular genera or species, may therefore be produced synthetically or recombinantly.

Variants

As used herein, the term “variant” refers to polynucleotide or polypeptide sequences different from the specifically identified sequences, wherein one or more nucleotides or amino acid residues is deleted, substituted, or added. Variants may be naturally occurring allelic variants, or non-naturally occurring variants. Variants may be from the same or from other species and may encompass homologues, paralogues and orthologues. In certain embodiments, variants of the inventive polypeptides and polypeptides possess biological activities that are the same or similar to those of the inventive polypeptides or polypeptides. The term “variant” with reference to polypeptides and polypeptides encompasses all forms of polypeptides and polypeptides as defined herein.

Polynucleotide Variants

Variant polynucleotide sequences preferably exhibit at least 50%, more preferably at least 51%, more preferably at least 52%, more preferably at least 53%, more preferably at least 54%, more preferably at least 55%, more preferably at least 56%, more preferably at least 57%, more preferably at least 58%, more preferably at least 59%, more preferably at least 60%, more preferably at least 61%, more preferably at least 62%, more preferably at least 63%, more preferably at least 64%, more preferably at least 65%, more preferably at least 66%, more preferably at least 67%, more preferably at least 68%, more preferably at least 69%, more preferably at least 70%, more preferably at least 71%, more preferably at least 72%, more preferably at least 73%, more preferably at least 74%, more preferably at least 75%, more preferably at least 76%, more preferably at least 77%, more preferably at least 78%, more preferably at least 79%, more preferably at least 80%, more preferably at least 81%, more preferably at least 82%, more preferably at least 83%, more preferably at least 84%, more preferably at least 85%, more preferably at least 86%, more preferably at least 87%, more preferably at least 88%, more preferably at least 89%, more preferably at least 90%, more preferably at least 91%, more preferably at least 92%, more preferably at least 93%, more preferably at least 94%, more preferably at least 95%, more preferably at least 96%, more preferably at least 97%, more preferably at least 98%, and most preferably at least 99% identity to a specified polynucleotide sequence. Identity is found over a comparison window of at least 20 nucleotide positions, preferably at least 50 nucleotide positions, more preferably at least 100 nucleotide positions, and most preferably over the entire length of the specified polynucleotide sequence.

Polynucleotide sequence identity can be determined in the following manner. The subject polynucleotide sequence is compared to a candidate polynucleotide sequence using BLASTN (from the BLAST suite of programs, version 2.2.5 [Nov. 2002]) in bl2seq (Tatiana A. Tatusova, Thomas L. Madden (1999), “Blast 2 sequences—a new tool for comparing protein and nucleotide sequences”, FEMS Microbiol Lett. 174:247-250), which is publicly available from NCBI (ftp://ftp.ncbi.nih.gov/blast/). The default parameters of bl2seq are utilized except that filtering of low complexity parts should be turned off.

The identity of polynucleotide sequences may be examined using the following unix command line parameters:

bl2seq -i nucleotideseq1 -j nucleotideseq2 -F F -p blastn

The parameter -F F turns off filtering of low complexity sections. The parameter -p selects the appropriate algorithm for the pair of sequences. The bl2seq program reports sequence identity as both the number and percentage of identical nucleotides in a line “Identities=”.

Polynucleotide sequence identity may also be calculated over the entire length of the overlap between a candidate and subject polynucleotide sequences using global sequence alignment programs (e.g. Needleman, S. B. and Wunsch, C. D. (1970) J. Mol. Biol. 48, 443-453). A full implementation of the Needleman-Wunsch global alignment algorithm is found in the needle program in the EMBOSS package (Rice, P. Longden, I. and Bleasby, A. EMBOSS: The European Molecular Biology Open Software Suite, Trends in Genetics June 2000, vol 16, No 6. pp. 276-277) which can be obtained from http://www.hgmp.mrc.ac.uk/Software/EMBOSS/. The European Bioinformatics Institute server also provides the facility to perform EMBOSS-needle global alignments between two sequences on line at http:/www.ebi.ac.uk/emboss/align/.

Alternatively the GAP program may be used which computes an optimal global alignment of two sequences without penalizing terminal gaps. GAP is described in the following paper: Huang, X. (1994) On Global Sequence Alignment. Computer Applications in the Biosciences 10, 227-235.

Polynucleotide variants of the present invention also encompass those which exhibit a similarity to one or more of the specifically identified sequences that is likely to preserve the functional equivalence of those sequences and which could not reasonably be expected to have occurred by random chance. Such sequence similarity with respect to polypeptides may be determined using the publicly available bl2seq program from the BLAST suite of programs (version 2.2.5 [Nov. 2002]) from NCBI (ftp://ftp.ncbi.nih.gov/blast/).

The similarity of polynucleotide sequences may be examined using the following unix command line parameters:

bl2seq -i nucleotideseq1 -j nucleotideseq2 -F F -p tblastx

The parameter -F F turns off filtering of low complexity sections. The parameter -p selects the appropriate algorithm for the pair of sequences. This program finds regions of similarity between the sequences and for each such region reports an “E value” which is the expected number of times one could expect to see such a match by chance in a database of a fixed reference size containing random sequences. The size of this database is set by default in the bl2seq program. For small E values, much less than one, the E value is approximately the probability of such a random match.

Variant polynucleotide sequences preferably exhibit an E value of less than 1×10⁻¹⁰ more preferably less than 1×10⁻²⁰, more preferably less than 1×10⁻³⁰, more preferably less than 1×10⁻⁴⁰, more preferably less than 1×10⁻⁵⁰, more preferably less than 1×10⁻⁶⁰, more preferably less than 1×10⁻⁷⁰, more preferably less than 1×10⁻⁸⁰, more preferably less than 1×10⁻⁹⁰, more preferably less than 1×10⁻¹⁰⁰, more preferably less than 1×10⁻¹¹⁰, and most preferably less than 1×10⁻¹²⁰ when compared with any one of the specifically identified sequences.

Alternatively, variant polynucleotides of the present invention hybridize to a specified polynucleotide sequence, or complements thereof under stringent conditions.

The term “hybridize under stringent conditions”, and grammatical equivalents thereof, refers to the ability of a polynucleotide molecule to hybridize to a target polynucleotide molecule (such as a target polynucleotide molecule immobilized on a DNA or RNA blot, such as a Southern blot or Northern blot) under defined conditions of temperature and salt concentration. The ability to hybridize under stringent hybridization conditions can be determined by initially hybridizing under less stringent conditions then increasing the stringency to the desired stringency.

With respect to polynucleotide molecules greater than about 100 bases in length, typical stringent hybridization conditions are no more than 25 to 30° C. (for example, 10° C.) below the melting temperature (Tm) of the native duplex (see generally, Sambrook et al., Eds, 1987, Molecular Cloning, A Laboratory Manual, 2nd Ed. Cold Spring Harbor Press; Ausubel et al., 1987, Current Protocols in Molecular Biology, Greene Publishing,). Tm for polynucleotide molecules greater than about 100 bases can be calculated by the formula Tm=81.5+0.41% (G+C−log(Na+). (Sambrook et al., Eds, 1987, Molecular Cloning, A Laboratory Manual, 2nd Ed. Cold Spring Harbor Press; Bolton and McCarthy, 1962, PNAS 84:1390). Typical stringent conditions for polynucleotide of greater than 100 bases in length would be hybridization conditions such as prewashing in a solution of 6×SSC, 0.2% SDS; hybridizing at 65° C., 6×SSC, 0.2% SDS overnight; followed by two washes of 30 minutes each in 1×SSC, 0.1% SDS at 65° C. and two washes of 30 minutes each in 0.2×SSC, 0.1% SDS at 65° C.

With respect to polynucleotide molecules having a length less than 100 bases, exemplary stringent hybridization conditions are 5 to 10° C. below Tm. On average, the Tm of a polynucleotide molecule of length less than 100 by is reduced by approximately (500/oligonucleotide length)° C.

With respect to the DNA mimics known as peptide nucleic acids (PNAs) (Nielsen et al., Science. 1991 Dec. 6; 254(5037):1497-500) Tm values are higher than those for DNA-DNA or DNA-RNA hybrids, and can be calculated using the formula described in Giesen et al., Nucleic Acids Res. 1998 Nov. 1; 26(21):5004-6. Exemplary stringent hybridization conditions for a DNA-PNA hybrid having a length less than 100 bases are 5 to 10° C. below the Tm.

Variant polynucleotides of the present invention also encompasses polynucleotides that differ from the sequences of the invention but that, as a consequence of the degeneracy of the genetic code, encode a polypeptide having similar activity to a polypeptide encoded by a polynucleotide of the present invention. A sequence alteration that does not change the amino acid sequence of the polypeptide is a “silent variation”. Except for ATG (methionine) and TGG (tryptophan), other codons for the same amino acid may be changed by art recognized techniques, e.g., to optimize codon expression in a particular host organism.

Polynucleotide sequence alterations resulting in conservative substitutions of one or several amino acids in the encoded polypeptide sequence without significantly altering its biological activity are also included in the invention. A skilled artisan will be aware of methods for making phenotypically silent amino acid substitutions (see, e.g., Bowie et al., 1990, Science 247, 1306).

Variant polynucleotides due to silent variations and conservative substitutions in the encoded polypeptide sequence may be determined using the publicly available bl2seq program from the BLAST suite of programs (version 2.2.5 [Nov. 2002]) from NCBI (ftp://ftp.ncbi.nih.gov/blast/) via the tblastx algorithm as previously described.

Polypeptide Variants

The term “variant” with reference to polypeptides encompasses naturally occurring, recombinantly and synthetically produced polypeptides. Variant polypeptide sequences preferably exhibit at least 50%, more preferably at least 51%, more preferably at least 52%, more preferably at least 53%, more preferably at least 54%, more preferably at least 55%, more preferably at least 56%, more preferably at least 57%, more preferably at least 58%, more preferably at least 59%, more preferably at least 60%, more preferably at least 61%, more preferably at least 62%, more preferably at least 63%, more preferably at least 64%, more preferably at least 65%, more preferably at least 66%, more preferably at least 67%, more preferably at least 68%, more preferably at least 69%, more preferably at least 70%, more preferably at least 71%, more preferably at least 72%, more preferably at least 73%, more preferably at least 74%, more preferably at least 75%, more preferably at least 76%, more preferably at least 77%, more preferably at least 78%, more preferably at least 79%, more preferably at least 80%, more preferably at least 81%, more preferably at least 82%, more preferably at least 83%, more preferably at least 84%, more preferably at least 85%, more preferably at least 86%, more preferably at least 87%, more preferably at least 88%, more preferably at least 89%, more preferably at least 90%, more preferably at least 91%, more preferably at least 92%, more preferably at least 93%, more preferably at least 94%, more preferably at least 95%, more preferably at least 96%, more preferably at least 97%, more preferably at least 98%, and most preferably at least 99% identity to a sequences of the present invention. Identity is found over a comparison window of at least 20 amino acid positions, preferably at least 50 amino acid positions, more preferably at least 100 amino acid positions, and most preferably over the entire length of a polypeptide of the invention.

Polypeptide sequence identity can be determined in the following manner. The subject polypeptide sequence is compared to a candidate polypeptide sequence using BLASTP (from the BLAST suite of programs, version 2.2.5 [Nov. 2002]) in bl2seq, which is publicly available from NCBI (ftp://ftp.ncbi.nih.gov/blast/). The default parameters of bl2seq are utilized except that filtering of low complexity regions should be turned off.

Polypeptide sequence identity may also be calculated over the entire length of the overlap between a candidate and subject polynucleotide sequences using global sequence alignment programs. EMBOSS-needle (available at http:/www.ebi.ac.uk/emboss/align/) and GAP (Huang, X. (1994) On Global Sequence Alignment. Computer Applications in the Biosciences 10, 227-235.) as discussed above are also suitable global sequence alignment programs for calculating polypeptide sequence identity.

Use of BLASTP as described above is preferred for use in the determination of polypeptide variants according to the present invention.

Polypeptide variants of the present invention also encompass those which exhibit a similarity to one or more of the specifically identified sequences that is likely to preserve the functional equivalence of those sequences and which could not reasonably be expected to have occurred by random chance. Such sequence similarity with respect to polypeptides may be determined using the publicly available bl2seq program from the BLAST suite of programs (version 2.2.5 [Nov. 2002]) from NCBI (ftp://ftp.ncbi.nih.gov/blast/). The similarity of polypeptide sequences may be examined using the following unix command line parameters:

bl2seq -i peptideseq1 -j peptideseq2 -F F -p blastp

Variant polypeptide sequences preferably exhibit an E value of less than 1×10⁻¹⁰ more preferably less than 1×10⁻²⁰, more preferably less than 1×10⁻³⁰, more preferably less than 1×10⁻⁴⁰, more preferably less than 1×10⁻⁵⁰, more preferably less than 1×10⁻⁶⁰, more preferably less than 1×10⁻⁷⁰, more preferably less than 1×10⁻⁸⁰, more preferably less than 1×10⁻⁹⁰, more preferably less than 1×10⁻¹⁰⁰ more preferably less than 1×10⁻¹¹⁰ more preferably less than 1×10⁻¹²⁰ more preferably less than 1×10⁻¹³⁰, more preferably less than 1×10⁻¹⁴⁰ more preferably less than 1×10⁻¹⁵⁰, more preferably less than 1×10⁻¹⁶⁰, more preferably less than 1×10⁻¹⁷⁰, more preferably less than 1×10⁻¹⁸⁰, more preferably less than 1×10⁻¹⁹⁰, more preferably less than 1×10⁻²⁰⁰, more preferably less than 1×10⁻²¹⁰, more preferably less than 1×10⁻²²⁰, and most preferably less than 1×10⁻²²² when compared with any one of the specifically identified sequences.

The parameter -F F turns off filtering of low complexity sections. The parameter -p selects the appropriate algorithm for the pair of sequences. This program finds regions of similarity between the sequences and for each such region reports an “E value” which is the expected number of times one could expect to see such a match by chance in a database of a fixed reference size containing random sequences. For small E values, much less than one, this is approximately the probability of such a random match.

Conservative substitutions of one or several amino acids of a described polypeptide sequence without significantly altering its biological activity are also included in the invention. A skilled artisan will be aware of methods for making phenotypically silent amino acid substitutions (see, e.g., Bowie et al., 1990, Science 247, 1306).

Constructs, Vectors and Components Thereof

The term “genetic construct” refers to a polynucleotide molecule, usually double-stranded DNA; which may have inserted into it another polynucleotide molecule (the insert polynucleotide molecule) such as, but not limited to, a cDNA molecule. A genetic construct may contain the necessary elements that permit transcribing the insert polynucleotide molecule, and, optionally, translating the transcript into a polypeptide. The insert polynucleotide molecule may be derived from the host cell, or may be derived from a different cell or organism and/or may be a recombinant polynucleotide. Once inside the host cell the genetic construct may become integrated in the host chromosomal DNA. The genetic construct may be linked to a vector.

The term “vector” refers to a polynucleotide molecule, usually double stranded DNA, which is used to transport the genetic construct into a host cell. The vector may be capable of replication in at least one additional host system, such as E. coli.

The term “expression construct” refers to a genetic construct that includes the necessary elements that permit transcribing the insert polynucleotide molecule, and, optionally, translating the transcript into a polypeptide. An expression construct typically comprises in a 5′ to 3′ direction:

-   -   a) a promoter functional in the host cell into which the         construct will be transformed,     -   b) the polynucleotide to be expressed, and     -   c) a terminator functional in the host cell into which the         construct will be transformed.

The term “coding region” or “open reading frame” (ORF) refers to the sense strand of a genomic DNA sequence or a cDNA sequence that is capable of producing a transcription product and/or a polypeptide under the control of appropriate regulatory sequences. The coding sequence is identified by the presence of a 5′ translation start codon and a 3′ translation stop codon. When inserted into a genetic construct, a “coding sequence” is capable of being expressed when it is operably linked to promoter and terminator sequences.

“Operably-linked” means that the sequenced to be expressed is placed under the control of regulatory elements that include promoters, tissue-specific regulatory elements, temporal regulatory elements, enhancers, repressors and terminators.

The term “noncoding region” refers to untranslated sequences that are upstream of the translational start site and downstream of the translational stop site. These sequences are also referred to respectively as the 5′ UTR and the 3′ UTR. These regions include elements required for transcription initiation and termination and for regulation of translation efficiency.

Terminators are sequences, which terminate transcription, and are found in the 3′ untranslated ends of genes downstream of the translated sequence. Terminators are important determinants of mRNA stability and in some cases have been found to have spatial regulatory functions.

The term “promoter” refers to nontranscribed cis-regulatory elements upstream of the coding region that regulate gene transcription. Promoters comprise cis-initiator elements which specify the transcription initiation site and conserved boxes such as the TATA box, and motifs that are bound by transcription factors.

A “transgene” is a polynucleotide that is taken from one organism and introduced into a different organism by transformation. The transgene may be derived from the same species or from a different species as the species of the organism into which the transgene is introduced.

An “inverted repeat” is a sequence that is repeated, where the second half of the repeat is in the complementary strand, e.g.,

(5′)GATCTA.......TAGATC(3′) (3′)CTAGAT.......ATCTAG(5′)

Read-through transcription will produce a transcript that undergoes complementary base-pairing to form a hairpin structure provided that there is a 3-5 bp spacer between the repeated regions.

A “transgenic plant” refers to a plant which contains new genetic material as a result of genetic manipulation or transformation. The new genetic material may be derived from a plant of the same species as the resulting transgenic plant or from a different species.

The terms “to alter expression of” and “altered expression” of a polynucleotide or polypeptide of the invention, are intended to encompass the situation where genomic DNA corresponding to a polynucleotide of the invention is modified thus leading to altered expression of a polynucleotide or polypeptide of the invention. Modification of the genomic DNA may be through genetic transformation or other methods known in the art for inducing mutations. The “altered expression” can be related to an increase or decrease in the amount of messenger RNA and/or polypeptide produced and may also result in altered activity of a polypeptide due to alterations in the sequence of a polynucleotide and polypeptide produced.

The term “seed yield” refers to the size and/or mass and/or number of seed or grain produced by a plant. Thus a plant with increased seed yield has increased size and/or mass and/or number of seed or grain relative to a suitable control plant at the same age or an equivalent developmental stage. Conversely, a plant with decreased seed yield has increased size and/or mass and/or number of seed or grain relative to a suitable control plant the same age or an equivalent development stage.

Suitable control plants may include non-transformed plants of the same species and variety, or plants of the same species or variety transformed with a control construct.

The term “altered” with reference to seed yield is intended to encompass either a decrease or increase in seed yield.

The term “modulating” with reference to seed yield is intended to encompass either decreasing or increasing seed yield.

The invention provides methods for producing and/or selecting plants with altered seed yield relative to suitable control plants, including plants with both increased and decreased seed yield and plants produced by such methods.

The invention provides a polynucleotide (SEQ ID NO: 34) encoding a polypeptide (SEQ ID NO:1) which modulates seed yield in plants. The invention provides polynucleotide variants of SEQ ID NO:34 (SEQ ID NO: 35 to 65) which encode polypeptide variants of SEQ ID NO: 1 (SEQ ID NO:2 to 31). The applicants have also identified a consensus polypeptide sequence (SEQ ID NO: 32) present in SEQ ID NO: 1 to 31 and a second consensus polypeptide sequence (SEQ ID NO:33) present in the sequences from monocotyledonous plants selected from within SEQ ID NO:1 to 31.

Methods for Isolating or Producing Polynucleotides

The polynucleotide molecules of the invention can be isolated by using a variety of techniques known to those of ordinary skill in the art. By way of example, such polynucleotides can be isolated through use of the polymerase chain reaction (PCR) described in Mullis et al., Eds. 1994 The Polymerase Chain Reaction, Birkhauser, incorporated herein by reference. The polypeptides of the invention can be amplified using primers, as defined herein, derived from the polynucleotide sequences of the invention.

Further methods for isolating polynucleotides, of the invention or useful in the methods of the invention, include use of all, or portions of, the polynucleotides set forth herein as hybridization probes. The technique of hybridizing labeled polynucleotide probes to polynucleotides immobilized on solid supports such as nitrocellulose filters or nylon membranes, can be used to screen the genomic or cDNA libraries. Exemplary hybridization and wash conditions are: hybridization for 20 hours at 65° C. in 5.0×SSC, 0.5% sodium dodecyl sulfate, 1X Denhardt's solution; washing (three washes of twenty minutes each at 55° C.) in 1.0×SSC, 1% (w/v) sodium dodecyl sulfate, and optionally one wash (for twenty minutes) in 0.5 X SSC, 1% (w/v) sodium dodecyl sulfate, at 60° C. An optional further wash (for twenty minutes) can be conducted under conditions of 0.1×SSC, 1% (w/v) sodium dodecyl sulfate, at 60° C.

The polynucleotide fragments of the invention may be produced by techniques well-known in the art such as restriction endonuclease digestion and oligonucleotide synthesis.

A partial polynucleotide sequence may be used, in methods well-known in the art to identify the corresponding full length polynucleotide sequence. Such methods include PCR-based methods, 5′RACE (Frohman M A, 1993, Methods Enzymol. 218: 340-56) and hybridization-based method, computer/database-based methods. Further, by way of example, inverse PCR permits acquisition of unknown sequences, flanking the polynucleotide sequences disclosed herein, starting with primers based on a known region (Triglia et al., 1998, Nucleic Acids Res 16, 8186, incorporated herein by reference). The method uses several restriction enzymes to generate a suitable fragment in the known region of a gene. The fragment is then circularized by intramolecular ligation and used as a PCR template. Divergent primers are designed from the known region. In order to physically assemble full-length clones, standard molecular biology approaches can be utilized (Sambrook et al., Molecular Cloning: A Laboratory Manual, 2nd Ed. Cold Spring Harbor Press, 1987).

It may be beneficial, when producing a transgenic plant from a particular species, to transform such a plant with a sequence or sequences derived from that species. The benefit may be to alleviate public concerns regarding cross-species transformation in generating transgenic organisms. Additionally when down-regulation of a gene is the desired result, it may be necessary to utilise a sequence identical (or at least highly similar) to that in the plant, for which reduced expression is desired. For these reasons among others, it is desirable to be able to identify and isolate orthologues of a particular gene in several different plant species. Variants (including orthologues) may be identified by the methods described.

Methods for Identifying Variants Physical Methods

Variant polynucleotides may be identified using PCR-based methods (Mullis et al., Eds. 1994 The Polymerase Chain Reaction, Birkhauser). Typically, the polynucleotide sequence of a primer, useful to amplify variant polynucleotide molecules PCR, may be based on a sequence encoding a conserved region of the corresponding amino acid sequence.

Alternatively library screening methods, well known to those skilled in the art, may be employed (Sambrook et al., Molecular Cloning: A Laboratory Manual, 2nd Ed. Cold Spring Harbor Press, 1987). When identifying variants of the probe sequence, hybridization and/or wash stringency will typically be reduced relatively to when exact sequence matches are sought.

Polypeptide variants may also be identified by physical methods, for example by screening expression libraries using antibodies raised against polypeptides of the invention (Sambrook et al., Molecular Cloning: A Laboratory Manual, 2nd Ed. Cold Spring Harbor Press, 1987) or by identifying polypeptides from natural sources with the aid of such antibodies.

Computer Based Methods

Polynucleotide and polypeptide variants, may also be identified by computer-based methods well-known to those skilled in the art, using public domain sequence alignment algorithms and sequence similarity search tools to search sequence databases (public domain databases include Genbank, EMBL, Swiss-Prot, PIR and others). See, e.g., Nucleic Acids Res. 29: 1-10 and 11-16, 2001 for examples of online resources. Similarity searches retrieve and align target sequences for comparison with a sequence to be analyzed (i.e., a query sequence). Sequence comparison algorithms use scoring matrices to assign an overall score to each of the alignments.

An exemplary family of programs useful for identifying variants in sequence databases is the BLAST suite of programs (version 2.2.5 [Nov. 2002]) including BLASTN, BLASTP, BLASTX, tBLASTN and tBLASTX, which are publicly available from (ftp://ftp.ncbi.nih.gov/blast/) or from the National Center for Biotechnology Information (NCBI), National Library of Medicine, Building 38A, Room 8N805, Bethesda, Md. 20894 USA. The NCBI server also provides the facility to use the programs to screen a number of publicly available sequence databases. BLASTN compares a nucleotide query sequence against a nucleotide sequence database. BLASTP compares an amino acid query sequence against a protein sequence database. BLASTX compares a nucleotide query sequence translated in all reading frames against a protein sequence database. tBLASTN compares a protein query sequence against a nucleotide sequence database dynamically translated in all reading frames. tBLASTX compares the six-frame translations of a nucleotide query sequence against the six-frame translations of a nucleotide sequence database. The BLAST programs may be used with default parameters or the parameters may be altered as required to refine the screen.

The use of the BLAST family of algorithms, including BLASTN, BLASTP, and BLASTX, is described in the publication of Altschul et al., Nucleic Acids Res. 25: 3389-3402, 1997.

The “hits” to one or more database sequences by a queried sequence produced by BLASTN, BLASTP, BLASTX, tBLASTN, tBLASTX, or a similar algorithm, align and identify similar portions of sequences. The hits are arranged in order of the degree of similarity and the length of sequence overlap. Hits to a database sequence generally represent an overlap over only a fraction of the sequence length of the queried sequence.

The BLASTN, BLASTP, BLASTX, tBLASTN and tBLASTX algorithms also produce “Expect” values for alignments. The Expect value (E) indicates the number of hits one can “expect” to see by chance when searching a database of the same size containing random contiguous sequences. The Expect value is used as a significance threshold for determining whether the hit to a database indicates true similarity. For example, an E value of 0.1 assigned to a polynucleotide hit is interpreted as meaning that in a database of the size of the database screened, one might expect to see 0.1 matches over the aligned portion of the sequence with a similar score simply by chance. For sequences having an E value of 0.01 or less over aligned and matched portions, the probability of finding a match by chance in that database is 1% or less using the BLASTN, BLASTP, BLASTX, tBLASTN or tBLASTX algorithm.

Multiple sequence alignments of a group of related sequences can be carried out with DbCLUSTAL (Thompson J. D., Plewnial F., Thierry J.-C. and Poch O. (2000) Rapid and reliable global multiple alignments of protein sequences detected by database searches. Nucleic Acid Research, Vol. 28, No 15: 2919-2926, http://www.ebi.ac.uk/cgi-bin/dbclustal/submit) or CLUSTALW (Thompson, J. D., Higgins, D. G. and Gibson, T. J. (1994) CLUSTALW: improving the sensitivity of progressive multiple sequence alignment through sequence weighting, positions-specific gap penalties and weight matrix choice. Nucleic Acids Research, 22:4673-4680, http://www-igbmc.u-strasbg.fr/BioInfo/ClustalW/Top.html) or T-COFFEE (Cedric Notredame, Desmond G. Higgins, Jaap Hering a, T-Coffee: A novel method for fast and accurate multiple sequence alignment, J. Mol. Biol. (2000) 302: 205-217)) or PILEUP, which uses progressive, pairwise alignments. (Feng and Doolittle, 1987, J. Mol. Evol. 25, 351).

Pattern recognition software applications are available for finding motifs or signature sequences. For example, MEME (Multiple Em for Motif Elicitation) finds motifs and signature sequences in a set of sequences, and MAST (Motif Alignment and Search Tool) uses these motifs to identify similar or the same motifs in query sequences. The MAST results are provided as a series of alignments with appropriate statistical data and a visual overview of the motifs found. MEME and MAST were developed at the University of California, San Diego.

PROSITE (Bairoch and Bucher, 1994, Nucleic Acids Res. 22, 3583; Hofmann et al., 1999, Nucleic Acids Res. 27, 215) is a method of identifying the functions of uncharacterized proteins translated from genomic or cDNA sequences. The PROSITE database (www.expasy.org/prosite) contains biologically significant patterns and profiles and is designed so that it can be used with appropriate computational tools to assign a new sequence to a known family of proteins or to determine which known domain(s) are present in the sequence (Falquet et al., 2002, Nucleic Acids Res. 30, 235). Prosearch is a tool that can search SWISS-PROT and EMBL databases with a given sequence pattern or signature.

Methods for Isolating Polypeptides

The polypeptides of the invention, including variant polypeptides, may be prepared using peptide synthesis methods well known in the art such as direct peptide synthesis using solid phase techniques (e.g. Stewart et al., 1969, in Solid-Phase Peptide Synthesis, WH Freeman Co, San Francisco Calif., or automated synthesis, for example using an Applied Biosystems 431A Peptide Synthesizer (Foster City, Calif.). Mutated forms of the polypeptides may also be produced during such syntheses.

The polypeptides and variant polypeptides of the invention may also be purified from natural sources using a variety of techniques that are well known in the art (e.g. Deutscher, 1990, Ed, Methods in Enzymology, Vol. 182, Guide to Protein Purification).

Alternatively the polypeptides and variant polypeptides of the invention may be expressed recombinantly in suitable host cells and separated from the cells as discussed below.

Methods for Producing Constructs and Vectors

The genetic constructs of the present invention comprise one or more polynucleotide sequences of the invention and/or polynucleotides encoding polypeptides of the invention, and may be useful for transforming, for example, bacterial, fungal, insect, mammalian or plant organisms. The genetic constructs of the invention are intended to include expression constructs as herein defined.

Methods for producing and using genetic constructs and vectors are well known in the art and are described generally in Sambrook et al., Molecular Cloning: A Laboratory Manual, 2nd Ed. Cold Spring Harbor Press, 1987; Ausubel et al., Current Protocols in Molecular Biology, Greene Publishing, 1987).

Methods for Producing Host Cells Comprising Constructs and Vectors

The invention provides a host cell which comprises a genetic construct or vector of the invention. Host cells may be derived from, for example, bacterial, fungal, insect, mammalian or plant organisms.

Host cells comprising genetic constructs, such as expression constructs, of the invention are useful in methods well known in the art (e.g. Sambrook et al., Molecular Cloning: A Laboratory Manual, 2nd Ed. Cold Spring Harbor Press, 1987; Ausubel et al., Current Protocols in Molecular Biology, Greene Publishing, 1987) for recombinant production of polypeptides of the invention. Such methods may involve the culture of host cells in an appropriate medium in conditions suitable for or conducive to expression of a polypeptide of the invention. The expressed recombinant polypeptide, which may optionally be secreted into the culture, may then be separated from the medium, host cells or culture medium by methods well known in the art (e.g. Deutscher, Ed, 1990, Methods in Enzymology, Vol 182, Guide to Protein Purification).

Host cells of the invention may also be useful in methods for production of an enzymatic product generated by an expressed polypeptide of the invention. Such methods may involve culturing the host cells of the invention in a medium suitable for expression of a recombinant polypeptide of the invention, optionally in the presence of additional enzymatic substrate for the expressed polypeptide of the invention. The enzymatic product produced may then be separated from the host cells or medium by a variety of art standard methods.

Methods for Producing Plant Cells and Plants Comprising Constructs and Vectors

The invention further provides plant cells which comprise a genetic construct of the invention, and plant cells modified to alter expression of a polynucleotide or polypeptide of the invention. Plants comprising such cells also form an aspect of the invention.

Production of plants altered in seed yield may be achieved through methods of the invention. Such methods may involve the transformation of plant cells and plants, with a construct designed to alter expression of a polynucleotide or polypeptide capable of modulating seed yield in such plant cells and plants. Such methods also include the transformation of plant cells and plants with a combination of constructs designed to alter expression of one or more polypeptides or polypeptides capable of modulating seed yield in such plant cells and plants.

Methods for transforming plant cells, plants and portions thereof with polynucleotides are described in Draper et al., 1988, Plant Genetic Transformation and Gene Expression. A Laboratory Manual, Blackwell Sci. Pub. Oxford, p. 365; Potrykus and Spangenburg, 1995, Gene Transfer to Plants. Springer-Verlag, Berlin; and Gelvin et al., 1993, Plant Molecular Biol. Manual. Kluwer Acad. Pub. Dordrecht. A review of transgenic plants, including transformation techniques, is provided in Galun and Breiman, 1997, Transgenic Plants. Imperial College Press, London.

Methods for Genetic Manipulation of Plants

A number of strategies for genetically manipulating plants are available (e.g. Birch, 1997, Ann Rev Plant Phys Plant Mol Biol, 48, 297). For example, strategies may be designed to increase expression of a polynucleotide/polypeptide in a plant cell, organ and/or at a particular developmental stage where/when it is normally expressed or to ectopically express a polynucleotide/polypeptide in a cell, tissue, organ and/or at. a particular developmental stage which/when it is not normally expressed. The expressed polynucleotide/polypeptide may be derived from the plant species to be transformed or may be derived from a different plant species.

Transformation strategies may be designed to reduce expression of a polynucleotide/polypeptide in a plant cell, tissue, organ or at a particular developmental stage which/when it is normally expressed. Such strategies are known as gene silencing strategies.

Genetic constructs for expression of genes in transgenic plants typically include promoters for driving the expression of one or more cloned polynucleotide, terminators and selectable marker sequences to detest presence of the genetic construct in the transformed plant.

The promoters suitable for use in the constructs of this invention are functional in a cell, tissue or organ of a monocot or dicot plant and include cell-, tissue- and organ-specific promoters, cell cycle specific promoters, temporal promoters, inducible promoters, constitutive promoters that are active in most plant tissues, and recombinant promoters. Choice of promoter will depend upon the temporal and spatial expression of the cloned polynucleotide, so desired. The promoters may be those normally associated with a transgene of interest, or promoters which are derived from genes of other plants, viruses, and plant pathogenic bacteria and fungi. Those skilled in the art will, without undue experimentation, be able to select promoters that are suitable for use in modifying and modulating plant traits using genetic constructs comprising the polynucleotide sequences of the invention. Examples of constitutive plant promoters include the CaMV 35S promoter, the nopaline synthase promoter and the octopine synthase promoter, and the Ubi 1 promoter from maize. Plant promoters which are active in specific tissues, respond to internal developmental signals or external abiotic or biotic stresses are described in the scientific literature. Exemplary promoters are described, e.g., in WO 02/00894, which is herein incorporated by reference.

Exemplary terminators that are commonly used in plant transformation genetic construct include, e.g., the cauliflower mosaic virus (CaMV) 35S terminator, the Agrobacterium tumefaciens nopaline synthase or octopine synthase terminators, the Zea mays zin gene terminator, the Oryza sativa ADP-glucose pyrophosphorylase terminator and the Solanum tuberosum PI-II terminator.

Selectable markers commonly used in plant transformation include the neomycin phophotransferase II gene (NPT II) which confers kanamycin resistance, the aadA gene, which confers spectinomycin and streptomycin resistance, the phosphinothricin acetyl transferase (bar gene) for Ignite (AgrEvo) and Basta (Hoechst) resistance, and the hygromycin phosphotransferase gene (hpt) for hygromycin resistance.

Use of genetic constructs comprising reporter genes (coding sequences which express an activity that is foreign to the host, usually an enzymatic activity and/or a visible signal (e.g., luciferase, GUS, GFP) which may be used for promoter expression analysis in plants and plant tissues are also contemplated. The reporter gene literature is reviewed in Herrera-Estrella et al., 1993, Nature 303, 209, and Schrott, 1995, In: Gene Transfer to Plants (Potrykus, T., Spangenbert. Eds) Springer Verlag. Berline, pp. 325-336.

Gene silencing strategies may be focused on the gene itself or regulatory elements which effect expression of the encoded polypeptide. “Regulatory elements” is used here in the widest possible sense and includes other genes which interact with the gene of interest.

Genetic constructs designed to decrease or silence the expression of a polynucleotide/polypeptide of the invention may include an antisense copy of a polynucleotide of the invention. In such constructs the polynucleotide is placed in an antisense orientation with respect to the promoter and terminator.

An “antisense” polynucleotide is obtained by inverting a polynucleotide or a segment of the polynucleotide so that the transcript produced will be complementary to the mRNA transcript of the gene, e.g.,

5′GATCTA 3′ 3′CTAGAT 5′ (coding strand) (antisense strand) 3′CUAGAU 5′ 5′GAUCUCG 3′ mRNA antisense RNA

Genetic constructs designed for gene silencing may also include an inverted repeat. An ‘inverted repeat’ is a sequence that is repeated where the second half of the repeat is in the complementary strand, e.g.,

5′-GATCTA.........TAGATC-3′ 3′-CTAGAT.........ATCTAG-5′

The transcript formed may undergo complementary base pairing to form a hairpin structure. Usually a spacer of at least 3-5 bp between the repeated region is required to allow hairpin formation.

Another silencing approach involves the use of a small antisense RNA targeted to the transcript equivalent to an miRNA (Llave et al., 2002, Science 297, 2053). Use of such small antisense RNA corresponding to polynucleotide of the invention is expressly contemplated.

The term genetic construct as used herein also includes small antisense RNAs and other such polypeptides effecting gene silencing.

Transformation with an expression construct, as herein defined, may also result in gene silencing through a process known as sense suppression (e.g. Napoli et al., 1990, Plant Cell 2, 279; de Carvalho Niebel et al., 1995, Plant Cell, 7, 347). In some cases sense suppression may involve over-expression of the whole or a partial coding sequence but may also involve expression of non-coding region of the gene, such as an intron or a 5′ or 3′ untranslated region (UTR). Chimeric partial sense constructs can be used to coordinately silence multiple genes (Abbott et al., 2002, Plant Physiol. 128(3): 844-53; Jones et al., 1998, Planta 204: 499-505). The use of such sense suppression strategies to silence the expression of a polynucleotide of the invention is also contemplated.

The polynucleotide inserts in genetic constructs designed for gene silencing may correspond to coding sequence and/or non-coding sequence, such as promoter and/or intron and/or 5′ or 3′ UTR sequence, or the corresponding gene.

Other gene silencing strategies include dominant negative approaches and the use of ribozyme constructs (McIntyre, 1996, Transgenic Res, 5, 257)

Pre-transcriptional silencing may be brought about through mutation of the gene itself or its regulatory elements. Such mutations may include point mutations, frameshifts, insertions, deletions and substitutions.

The following are representative publications disclosing genetic transformation protocols that can be used to genetically transform the following plant species: Rice (Alam et al., 1999, Plant Cell Rep. 18, 572); maize (U.S. Pat. Nos. 5,177,010 and 5,981,840); wheat (Ortiz et al., 1996, Plant Cell Rep. 15, 1996, 877); tomato (U.S. Pat. No. 5,159,135); potato (Kumar et al., 1996 Plant J. 9: 821); cassaya (Li et al., 1996 Nat. Biotechnology 14, 736); lettuce (Michelmore et al., 1987, Plant Cell Rep. 6, 439); tobacco (Horsch et al., 1985, Science 227, 1229); cotton (U.S. Pat. Nos. 5,846,797 and 5,004,863); grasses (U.S. Pat. Nos. 5,187,073, 6,020,539); peppermint (Niu et al., 1998, Plant Cell Rep. 17, 165); citrus plants (Pena et al., 1995; Plant Sci. 104, 183); caraway (Krens et al., 1997, Plant Cell Rep, 17, 39); banana (U.S. Pat. No. 5,792,935); soybean (U.S. Pat. Nos. 5,416,011; 5,569,834; 5,824,877; 5,563,044,55 and 5,968,830); pineapple (U.S. Pat. No. 5,952,543); poplar (U.S. Pat. No. 4,795,855); monocots in general (U.S. Pat. Nos. 5,591,616 and 6,037,522); brassica (U.S. Pat. Nos. 5,188,985; 5,463,174 and 5,750,871); and cereals (U.S. Pat. No. 6,074,877). Other species are contemplated and suitable methods and protocols are available to in the scientific literature for use by those skilled in the art.

Several further methods known in the art may be employed to alter expression of a nucleotide and/or polypeptide of the invention. Such methods include but are not limited to Tilling (Till et al., 2003, Methods Mol Biol, 2%, 205), so called “Deletagene” technology (Li et al., 2001, Plant Journal 27(3), 235) and the use of artificial transcription factors such as synthetic zinc finger transcription factors. (e.g. Jouvenot et al., 2003, Gene Therapy 10, 513). Additionally antibodies or fragments thereof, targeted to a particular polypeptide may also be expressed in plants to modulate the activity of that polypeptide (Jobling et al., 2003, Nat. Biotechnol., 21(1), 35). Transposon tagging approaches may also be applied. Additionally peptides interacting with a polypeptide of the invention may be identified through technologies such as phase-display (Dyax Corporation). Such interacting peptides may be expressed in or applied to a plant to affect activity of a polypeptide of the invention. Use of each of the above approaches in alteration of expression of a nucleotide and/or polypeptide of the invention is specifically contemplated.

Methods for Selecting Plants

Methods are also provided for selecting plants with altered seed yield. Such methods involve testing of plants for altered for the expression of a polynucleotide or polypeptide of the invention. Such methods may be applied at a young age or early developmental stage when the altered seed yield may not necessarily be visible, to accelerate breeding programs directed toward improving seed yield.

The expression of a polynucleotide, such as a messenger RNA, is often used as an indicator of expression of a corresponding polypeptide. Exemplary methods for measuring the expression of a polynucleotide include but are not limited to Northern analysis, RT-PCR and dot-blot analysis (Sambrook et al., Molecular Cloning: A Laboratory Manual, 2nd Ed. Cold Spring Harbor Press, 1987). Polynucleotides or portions of the polynucleotides of the invention are thus useful as probes or primers, as herein defined, in methods for the identification of plants with altered seed yield. The polypeptides of the invention may be used as probes in hybridization experiments, or as primers in PCR based experiments, designed to identify such plants.

Alternatively antibodies may be raised against polypeptides of the invention. Methods for raising and using antibodies are standard in the art (see for example: Antibodies, A Laboratory Manual, Harlow A Lane, Eds, Cold Spring Harbour Laboratory, 1998). Such antibodies may be used in methods to detect altered expression of polypeptides which modulate seed yield in plants. Such methods may include ELISA (Kemeny, 1991, A Practical Guide to ELISA, NY Pergamon Press) and Western analysis (Towbin & Gordon, 1994, J Immunol Methods, 72, 313).

These approaches for analysis of polynucleotide or polypeptide expression and the selection of plants with altered expression are useful in conventional breeding programs designed to produce varieties with altered seed yield.

Plants

The plants of the invention may be grown and either self-ed or crossed with a different plant strain and the resulting hybrids, with the desired phenotypic characteristics, may be identified. Two or more generations may be grown to ensure that the subject phenotypic characteristics are stably maintained and inherited. Plants resulting from such standard breeding approaches also form an aspect of the present invention.

Seed yield in a plant may also be altered through methods of the invention. Such methods may involve the transformation of plant cells and plants, with a construct of the invention designed to alter expression of a polynucleotide or polypeptide which modulates seed yield in such plant cells and plants. Such methods also include the transformation of plant cells and plants with a combination of the construct of the invention and one or more other constructs designed to alter expression of one or more polynucleotides or polypeptides which modulates seed yield in plants.

Exemplary methods for assessing seed yield in plants are provided in Boyes D C et al., 2001, Plant Cell. 13(7):1499-510; Lancashire P. D et al., 1991, Ann. Appl. Biol. 119:560-601, and in Example 1 below.

This invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more said parts, elements or features, and where specific integers are mentioned herein which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be better understood with reference to the accompanying drawings in which:

FIG. 1 shows the output summary of a BLASTP search of the uniref100 database (version 2.0 MP-WashU [4 May 2006]) in which the ORF56 polypeptide was used as a seed sequence.

FIG. 2 shows a “Prettyplot” alignment of polypeptides (SEQ ID NO: 1 to 31) including ORF56 and variants thereof and illustrates a consensus region identified by the applicants which is present in all of the sequences.

FIG. 3 shows a “Prettyplot” alignment of polypeptides of the invention, including ORF56 SEQ ID NO:1 and sequences from all variants of SEQ ID NO:1 and illustrates a consensus GAD region identified by the applicants which is present in all of the such sequences.

FIG. 4 shows another “Prettyplot” alignment of polypeptides of the invention, including ORF 56 SEQ ID NO: 1 and sequence variants SEQ ID NO:2-31 and illustrates a consensus CaM region identified by the applicants which is present in all of the such sequences.

FIG. 5 shows a map of an over-expression vector, for plant transformation, comprising ORF56 cloned in sense orientation (SEQ ID NO:66).

FIG. 6 shows a DNA gel-blot analysis on genomic DNA from ORF56 T0 transgenic plants digested with a restriction enzyme and probed with a fragment of ORF56 coding sequence to determine gene copy number and to identify independent transformation events.

FIGS. 7 a-7 d show the growth parameters observed for transgenic ORF56 T1 plant lines compared to the best performing wild type control (Nipponbare). Where FIG. 7 a. Plant height measurements from experiment 1, FIG. 7 b. Plant tiller measurements from experiment 1, FIG. 7 c. Plant height measurements from experiment 2, FIG. 7 d. Plant tiller measurements from experiment 1.

FIGS. 8 a-8 e show the seed and grain characteristics for transgenic ORF56 T1 plant lines compared to the best performing wild type control (Nipponbare). Where FIG. 8 a, Seed yield per plant in different ORF56 T1 lines, FIG. 8 b Total number of seeds per plant in different ORF56 T1 lines, FIG. 8 c Average mass of an individual seed in each ORF56 T1 line, FIG. 8 d Binomial distribution for seed yields in different ORF56 T1 lines, FIG. 8 e Shift in seed yield distribution in the different ORF56 T1 lines.

FIG. 9 shows the seeds/grain harvested from the best yielding control plant (Nipponbare) and ORF56 T1 plant.

FIG. 10 shows an alignment of the ORF56 polypeptide sequence (SEQ ID NO: 1) and all of the other variants sequences disclosed that are from monocotyledonous species. The position of a completely conserved motif within the GAD region is shown. The sequence of the completely conserved motif is shown in SEQ ID NO: 32.

FIG. 11 shows an alignment of the ORF56 polypeptide sequence (SEQ ID NO: 1) and all of the other variant sequences disclosed that are from dicotyledonous species. The position of a completely conserved motif within the GAD region is shown. This sequence motif is completely conserved in all of the dicotyledonous sequences and all of the monocotyledonous sequences (see FIG. 10) and is shown on SEQ ID NO: 33.

EXAMPLES

The invention will now be illustrated with reference to the following non-limiting examples.

Example 1 Altered Seed Yield by in-Plant Expression of a Polynucleotide of the Invention ORF56

A polynucleotide designated ORF56 (SEQ ID NO:34) was identified in a ViaLactia Biosciences Ltd proprietary ryegrass (Lolium perenne) GeneThresher (Orion Genomics) genomic library. ORF56 appears to encode a polypeptide (SEQ ID NO:1) which is a glutamate decarboxylase (GAD). GAD catalyses the reaction of glutamate into carbon dioxide and gamma-aminobutyrate (GABA). GAD is believed to be essential for cytosolic pH regulation as well as basic morphological development. The synthesis of GABA is highly regulated under normal growth conditions and in response to stresses such as cold, heat, water or mechanical (Bouche et al 2004; Mayer et al 1990: Patterson and Graham 1987; Wallace et al. 1984). It has been shown that GABA stimulates ethylene production in sunflower, apparently by causing increases in ACC synthase mRNA accumulation, ACC levels, ACC oxidase mRNA levels and ACC oxidase activity, suggesting that GABA may play a role in signaling (Kathiresan et al 1997). High GABA has been reported to impair pollen tube growth, and consequently seed set, while lower levels are reported to be stimulatory (Updegraff and Preuss 2004). The glutamate decarboxylase encoded by ORF56 contains two major domains, the GAD catalytic domain and a second Calmodulin binding domain (CaM). CaM has been shown to stimulate GAD activity by binding to a C-terminal ‘extension’ not found in prokaryotes such as E. coli or mammalian forms of GAD. Truncation of this domain results in shorter, more branched plants with delayed greening and lacking pollen (Baum et al 1996; Akama and Takaiwa 2007). Post-translational modifications of GAD may account for different phenotypes observed. GAD is a monomer in aqueous solutions. Normally, the binding of a Trp residue in the hydrophobic region of the peptide to the C-terminal domain of CaM (boxed residue in FIG. 4) initiates the peptide complex formation. Subsequently, the N-terminal lobe of CaM binds to the hydrophobic and positively charged residues of the region of the peptide 10-12 residues away from the Trp residue (Yuan and Vogel 1998). However, in perennial ryegrass, SEQ ID: 1, the CaM binding domain, lacks the hydrophobic residue Trp, but instead is replaced with a polar but non-charged Cys residue in a hydrophobic setting. The negative charges in perennial ryegrass CaM domain are also disposed in such a way that interaction of the N-terminal lobe of CaM with the region either N- or C-terminal to the GAD would not be energetically favourable, thereby facilitating binding of a second or multiple GAD peptides to the hydrophobic surface in the N-terminal region of CaM. This essentially results in the dimerization or multimerization of the GAD-Ca²⁺-CaM complex. There are possibilities for the GAD such dimerization, which seems to be induced by Ca²⁺-CaM binding (Yuan and Vogel 1998). In plants, there is evidence for the oligomerization of petunia GAD and it appears that only oligomerized GAD seem to be active in petunia (Baum et al 1996). In addition, various isoforms of active GAD extracted from barley were reported to have a mass of ˜256 kDa and ˜120 kDa (Inatomi and Slaughter 1975). The activity of the barley GADs were also reported to exhibit a reversible inhibition in the presence of 2-Mercaptoethanol. Given these evidences, it is not unreasonable to expect the Cys residue, at the normally Trp residue position in the CaM domain, to play a role in stabilizing the dimerized GAD-Ca²⁺-CaM complex.

ORF56 Variants

The polypeptide sequence encoded by the ORF56 was used as seed sequence to perform WU-blastp search against uniref100 database (2.0 MP-WashU [4 May 2006]) to identify variants of ORF56. The WU-blastp output summary is shown in FIG. 1. A cut-off e value of less than or equal to 5.5e-169, was identified as distinguishing variants of ORF56 from unrelated proteins, based upon assessment of the associated score value and annotations in the public database. Selected variant sequences were aligned using the DbCLUSTAL (Thompson J. D., Plewnial F., Thierry J.-C. and Poch O.: 2000), which is an interface to the popular multiple alignment program ClustalW. Aligned sequences were visualised using another EMBOSS tool called Prettyplot as shown in FIG. 2.

The variant polypeptide sequences of ORF56 are listed as SEQ ID NO:2-31 in the sequence listing. The corresponding polynucleotide sequences are listed as SEQ ID NO: 35-65.

All but four of the variant polypeptide sequences appear to have both a proper GAD catalytic domain and a proper CaM binding domain. Four of the sequences (polypeptide SEQ ID NO: 11, 15, 22 and 29; polynucleotide SEQ ID NO:61 to 66) appear to have a proper GAD catalytic domain with a variant CaM binding domain.

A conserved GAD polypeptide sequence region present in ORF56 and all of the identified variants of ORF 56 was identified using Prettyplot alignment as shown in FIG. 3.

A further conserved CaM polypeptide sequence region present in polypeptide sequences SEQ ID NO: 1-31 was also identified using Prettyplot alignment as shown in FIG. 4.

A completely conserved polypeptide sequence motif was identified in the GAD region in all of the variant sequences, and is shown on SEQ ID NO: 32.

A completely conserved polypeptide sequence motif was also identified in the GAD region in all of the variant sequences that are from monocotyledonous species and is shown in SEQ ID NO: 33.

Construction of a Vector for Over-Expression of ORF56 Via Plant Transformation

A vector for over-expression ORF56 was produced by standard molecular biology techniques. A map of the binary vector is shown in FIG. 5. The sequence of the vector is shown in SEQ ID NO: 66.

Plant Transformation

Agrobacterium tumefaciens strains can be transformed with binary plasmid DNA using either a freeze/thaw (Chen et. al 1994) or electroporation method (den Dulk-Ras A and Hooykaas P J.). Purified plasmid DNA of ORF56 was introduced into Agrobacterium strain EHA105 by electroporation and the suspension was incubated at 26° C. for 30 minutes. A small aliquot was plated on AB minimal medium (Schmidt-Eisenlohr et. al 1999) containing Kanamycin at 100 mg/L. Plates were incubated at 26° C. for 3 days and single colonies were tested for presence of the plasmid using construct specific primers and transformation confirmed.

Agrobacterium cultures were grown in AG minimal medium containing 100 mg/L kanamycin at 26° C. with shaking (200 rpm). The Agrobacterium suspensions were pelleted at 5,000 rpm for 5 minutes, washed once in basal MS medium containing 1% glucose and 3% sucrose, pH 5.2, and re-suspended in same medium containing 200 μM acetosyringone to OD₆₀₀ 0.6-0.8.

A. tumefaciens containing the binary vector ORF56 were used to co-cultivate at least 1,000 immature rice (Oryza sativa) cv. Nipponbare embryos. Immature seeds from rice were washed in sterile water and then surface sterilized with sodium hypochlorite containing 1.25% active chlorine with 10 μl, Tween® 20 for 20 minutes. After sterilization, the seeds were washed several times with sterile water and blotted dry on sterile filter paper (3M). The seeds were de-husked manually using sterile pair of forceps and the embryo dissected out with sterile knife. The isolated embryos were immersed in Agrobacterium suspension for 30 minutes with continuous shaking at 100 rpm in a 10 mL culture tube. The excess liquid was drained off and the embryos blotted on to sterile filter paper before placing them on to co-cultivation medium containing MS medium (Murashige and Skoog, 1964) supplemented with 3% sucrose, 1% glucose, 2 mg/L 2,4-D, 0.1 mg/L BA, 400 μM acetosyringone, pH 5.2 for 4 days in dark. After co-cultivation, the calli forming embryos were sub-cultured once every two weeks on selection medium consisting of MS medium supplemented with 3% sucrose, 1% glucose, 2 mg/L 2,4-D (2,4-dichlorophenoxy acetic acid), 0.1 mg/L BA (benzyl adenine) and containing 50 mg/L hygromycin and 300 mg/L Timentin™ (ticarcillin+clavulanic acid) till at-least 30 healthy calli showing green spots indicative of healthy shoot emergence was achieved. Calli containing the green spots were transferred to selection medium lacking 2,4-D to regenerate a minimum of 10 transformed plants. Regenerated plants were rooted and then transplanted to six inch pots containing soil and plants grown in greenhouse. DNA gel-blot analysis was carried out (FIG. 6) to determine gene copy number and identify five independent transformation events. T1 seeds were harvested from the transformed plants (T0).

T1 Plant Phenotyping

Thirty seeds from Southern positive T0 plants were sown in individual cups containing cocopeat and twenty healthy plants out of them were transplanted in the green house. These plants were arranged using a CRD using the random numbers from a random table.

T1 plant phenotyping was carried out in two separate experiments. The first experiment involved progeny lines from T0 events 1129105 and 1129106 and Nipponbare (a wild-type control), and the second experiment involved progeny lines from T0 events 1129102, 1129103 and 112904 and Nipponbare (a wild-type control.)

Phenotypic Analysis of T0 Lines

The physiological state of T0 plants is presented in Table 1, below.

TABLE 1 Physiological measurements of T0 lines Pollen Productive Tillers/ Plant Seed T0 line fertility Total Number of Tillers height (cms) yield 1129102 72.2% 9/9 64.3 30 1129103 91.5% 14/15 69.6 30 1129104 79.7% 9/9 65.6 50 1129105 85.6% 8/8 84.2 130 1129106 81.5% 7/7 75.5 160

Phenotypic Analysis of T1 Lines

Plants height and tiller numbers were measured once every week post-transplanting until seed set was achieved. FIGS. 7 a, b, c and d depict the growth parameters observed for these plants. Transgenic ORF56 plants (T1) were not different in terms of plant height and tillering capacity based upon standard statistical analysis. Transgenic ORF56 plants can be said to be normal in all aspects assessed (data not shown) except for seed yield, which was found in one of the plant progenies analysed to be as high as 3.55 times the normal seed yield.

FIG. 8 a, b, c, d, and e describe the seed yield per plant, total number of seeds per plant, average mass of an individual seed in each line, binomial distribution for seed yields in different lines and shift in seed yield distribution in the lines analysed. It is evident from this analysis that the increase in seed yield is the result of an increase in seed number rather than an increase in individual seed weight (FIG. 8 a, b and c). Given that the analysis was carried out using the segregating population in T1, it is not surprising that a shift is observed in the binomial distribution for seed yield trait in the transgenic populations investigated (FIGS. 8 d and e). Conventional breeding techniques, such as single seed descent, can fix the trait for enhanced seed yield.

The seed yield from the best seed yielding plant from wild-type Nipponbare and the T10RF56 plant is presented in FIG. 9.

REFERENCES

-   Adams et al. 1991, Science 252:1651-1656. -   Akama, K and Takaiwa (2007) J Exp Bot.: 58 (10) 2699-2707. -   Baum G, Lev-Yadun S, Fridmann Y, Arazi T, Katsnelson H, Zik M, and     Fromm H (1996) EMBO J.: 15 (12) 2988-2996. -   Bouche N, Fait A, Zik M, Fromm H. (2004) Plant Mol. Biol.; 55 (3):     315-25. -   Chen H, Nelson R S, Sherwood J L. (1994) Biotechniques; 16 (4):     664-8, 670. -   Chen et al. 2002, Nucleic Acids Res. 31:101-105 -   den Dulk-Ras A, Hooykaas P J. (1995) Methods Mol. Biol.; 55: 63-72. -   Inatomi, K and Slaughter, J C (1975) Biochem J. 147: 479-484. -   Kathiresan A, Tung P, Chinnappa C C, Reid D M (1997) Plant Physiol.     115: 129-135. -   Lee et al. 2003, PNAS 99:12257-12262 -   Lee and Lee, 2003 Plant Physiol. 132: 517-529 -   Mayer R R, Cherry J H, Rhodes D (1990) Plant Physiol. 94: 796-810. -   Murashige T, Skoog F (1962) Physiol Plant 15: 473-497 -   Patterson B D, Graham D (1987) In (DD Davies ed) “The Biochemistry     of Plants”, Vol 12, Academic Press, New York, pp. 153-199. -   Richmond and Somerville 2000, Current Opinion in Plant Biology.     3:108-116 -   Ruan et al. 2004, Trends in Biotechnology 22: 23-30. -   Schmidt-Eisenlohr H, Domke N, Angerer C, Wanner G, Zambryski P C,     Baron C. (1999) J. Bacteriol.; 181 (24): 7485-92. -   Sun et al. 2004, BMC Genomics 5: 1.1-1.4 -   Thompson, J. D., Higgins, D. G. and Gibson, T. J. (1994) CABIOS, 10,     19-29. -   Updegraff E, Preuss D (2004) in International Arabidopsis     Conference, Germany -   Velculescu et al. 1995, Science 270: 484-487 -   Wallace W, Secor J, Schrader L E (1984) Plant Physiol. 75: 170-175. -   Yuan, T and Vogel, H J (1998) J. Biol. Chem. 273 (46) 30328-30335.

The above examples illustrate practice of the invention. It will be appreciated by those skilled in the art that numerous variations and modifications may be made without departing from the spirit and scope of the invention.

SUMMARY OF SEQUENCES

SEQ ID NO: Sequence type Information Species 1 polypeptide ORF 56 Lolium perenne 2 polypeptide UniRef100_Q42521 Arabidopsis thaliana Glutamate decarboxylase 1 3 polypeptide UniRef100_Q42472 Arabidopsis thaliana Glutamate decarboxylase 2 4 polypeptide UniRef100_Q07346 Petunia hybrida Glutamate decarboxylase 5 polypeptide UniRef100_P54767 Lycopersicon esculentum Glutamate decarboxylase 6 polypeptide UniRef100_A0EJ88 Populus tremula × Glutamate decarboxylase Populus alba 7 polypeptide UniRef100_A2XEB3 Oryza sativa subsp. Putative uncharacterized indica protein 8 polypeptide UniRef100_A3AM59 Oryza sativa subsp. Putative uncharacterized japonica protein 9 polypeptide UniRef100_A5BI27 Vitis vinifera Putative uncharacterized protein 10 polypeptide UniRef100_A7P433 Vitis vinifera Chromosome chr1 scaffold_5, whole genome shotgun sequence 11 polypeptide UniRef100_A7P434 Vitis vinifera Chromosome chr1 scaffold_5, whole genome shotgun sequence 12 polypeptide UniRef100_O81101 Nicotiana tabacum Glutamate decarboxylase isozyme 2 13 polypeptide UniRef100_O81102 Nicotiana tabacum Glutamate decarboxylase isozyme 1 14 polypeptide UniRef100_P93369 Nicotiana tabacum Glutamate decarboxylase 15 polypeptide UniRef100_Q01J81 Oryza sativa OSIGBa0152K17.6 16 polypeptide UniRef100_Q1I1D8 Citrus sinensis Glutamate decarboxylase 17 polypeptide UniRef100_Q6ASV4 Oryza sativa subsp. Putative glutamate japonica decarboxylase isozyme 18 polypeptide UniRef100_Q6Q4I1 Brassica juncea Glutamate decarboxylase 4b 19 polypeptide UniRef100_Q6Q4I2 Brassica juncea Glutamate decarboxylase 4a 20 polypeptide UniRef100_Q6Q4I3 Brassica juncea Glutamate decarboxylase 2 21 polypeptide UniRef100_Q6YSB2 Oryza sativa subsp. japonica 22 polypeptide UniRef100_Q7XZU7 Hordeum vulgare GAD1 23 polypeptide UniRef100_Q84U04 Oryza sativa subsp. Glutamate decarboxylase japonica 24 polypeptide UniRef100_Q8LFR4 Arabidopsis thaliana Glutamate decarboxylase, putative 25 polypeptide UniRef100_Q8LKR4 Nicotiana tabacum Glutamate decarboxylase 26 polypeptide UniRef100_Q944L6 Arabidopsis thaliana At1g65960/F12P19_12 27 polypeptide UniRef100_Q94KK8 Nicotiana tabacum Glutamate decarboxylase isozyme 3 28 polypeptide UniRef100_Q9AR41 Oryza sativa subsp. Glutamate decaroxylase japonica 29 polypeptide UniRef100_Q9AR41 Oryza sativa subsp. Glutamate decarboxylase japonica 30 polypeptide UniRef100_Q9AT17 Nicotiana tabacum Glutamate decarboxylase isozyme 1 31 polypeptide UniRef100_Q9LSH2 Arabidopsis thaliana Glutamate dearboxylase 32 polypeptide GAD plant consensus Artificial 33 polypeptide CaM monocot plant Artificial consensus 34 polynucleotide ORF 56 Lolium perenne 35 polynucleotide XP_462650.10 Oryza sativa 36 polynucleotide AAN46801.1 Arabidopsis thaliana 37 polynucleotide XP_482841.1 Oryza sativa 38 polynucleotide AAS79671.1 Brassica juncea 39 polynucleotide AAS79670.1 Brassica juncea 40 polynucleotide AAS79669.1 Brassica juncea 41 polynucleotide BAB02870.1 Arabidopsis thaliana 42 polynucleotide AAM70569.1 Arabidopsis thaliana 43 polynucleotide BAC42751.1 Arabidopsis thaliana 44 polynucleotide AAK38667.1 | AF353615_1 Nicotiana tabacum 45 polynucleotide AAK18620.1 | AF352732_1 Nicotiana tabacum 46 polynucleotide AAP85548.1 Glycine Max 47 polynucleotide AAM48129.1 | AF506366_1 Nicotiana tabacum 48 polynucleotide AAM61251.1 Arabidopsis thaliana 49 polynucleotide AAP79441.1 Oryza sativa 50 polynucleotide AAL91148.1 Arabidopsis thaliana 51 polynucleotide XP_482840.1 Oryza sativa 52 polynucleotide AAL16126.1 | AF428294_1 Arabidopsis thaliana 53 polynucleotide AAC39483.1 Nicotiana tabacum 54 polynucleotide AAM70582.1 Arabidopsis thaliana 55 polynucleotide AAC24195.1 Nicotiana tabacum 56 polynucleotide AAB40608.1 Nicotiana tabacum 57 polynucleotide AAA93132.1 Arabidopsis thaliana 58 polynucleotide A48767 Petunia hybrida 59 polynucleotide AAL83983.1 Oryza sativa 60 polynucleotide CAA56812.1 Lycopersicon esculentum 61 polynucleotide XP_462654.1 Oryza sativa 62 polynucleotide AAM7304.1 | AF377946_6 Oryza sativa 63 polynucleotide BAB32871.1 Oryza sativa 64 polynucleotide AAT77842.1 Oryza sativa 65 polynucleotide AAP46640.1 Hordeum vulgare 66 polynucleotide vector Artificial 67 polynucleotide U10034.1 | codes AAA93132 Arabidopsis thaliana and UniRef100_Q42521 68 polynucleotide U46665.1 | codes AAC33485 Arabidopsis thaliana and UniRef100_Q42472 69 polynucleotide L16797.1 codes AAA33709 Petunia × hybrida and UniRef100_Q07346 70 polynucleotide X80840.1 | codes CAA56812 Solanum lycopersicum and UniRef100_P54767 71 polynucleotide DQ125945.1 | codes Populus tremula × Populus alba ABA18652 and UniRef100_A0EJ88 72 polynucleotide CM000128.1 | codes Oryza sativa Indica EAY89173 and UniRef100_A2XEB3 73 polynucleotide CM000140.1 | codes Oryza sativa Japonica EAZ28398 and UniRef100_A3AM59 74 polynucleotide AM460203.2 | codes Vitis vinifera CAN67952 and UniRef100_A5BI27 75 polynucleotide CU459222.1 | codes Vitis vinifera CAO42441 and UniRef100_A7P433 76 polynucleotide CU459222.1 | codes Vitis vinifera CAO42442 and UniRef100_A7P434 77 polynucleotide AF020424.1 | codes Nicotiana tabacum AAC39483 and UniRef100_O81101 78 polynucleotide AF020425.1 | codes Nicotiana tabacum AAC24195 and UniRef100_O81102 79 polynucleotide U54774.1 | codes AAB40608 Nicotiana tabacum and UniRef100_P93369 80 polynucleotide CR855179.1 | codes Oryza sativa CAH67194 and UniRef100_Q01J81 81 polynucleotide DQ001727.1 | codes Citrus sinensis AAZ05070 and UniRef100_Q1I1D8 82 polynucleotide DP000009.2 | codes Oryza sativa Japonica ABF98584 and UniRef100_Q6ASV4 83 polynucleotide AY559320.1 | codes Brassica juncea AAS79671 and UniRef100_Q6Q4I1 84 polynucleotide AY559319.1 | codes Brassica juncea AAS79670 and UniRef100_Q6Q4I2 85 polynucleotide AY559318.1 | codes Brassica juncea AAS79669 and UniRef100_Q6Q4I3 86 polynucleotide AP006461.3 | codes Oryza sativa Japonica BAD10771 and UniRef100_Q6YSB2 87 polynucleotide AF521177.1 | codes Hordeum vulgare AAP46640 and UniRef100_Q7XZU7 88 polynucleotide AY318775.1 | codes Oryza sativa Japonica AAP79441 and UniRef100_Q84U04 89 polynucleotide AY084689.1 | codes Arabidopsis thaliana AAM61251 and UniRef100_Q8LFR4 90 polynucleotide AF506366.1 | codes Nicotiana tabacum AAM48129 and UniRef100_Q8LKR4 91 polynucleotide AF428294.1 | codes Arabidopsis thaliana AAL16126 and UniRef100_Q944L6 92 polynucleotide AF353615.1 | codes Nicotiana tabacum AAK38667 and UniRef100_Q94KK8 93 polynucleotide AB056061.1 | codes Oryza sativa Japonica BAB32869 and UniRef100_Q9AR41 94 polynucleotide AB056061.1 | codes Oryza sativa Japonica BAB32869 and UniRef100_Q9AR41 95 polynucleotide AF352732.1 | codes Nicotiana tabacum AAK18620 and UniRef100_Q9AT17 96 polynucleotide AB026646.1 | codes Arabidopsis thaliana BAB02870 and UniRef100_Q9LSH2 97 polypeptide XP_462650 Oryza sativa 98 polypeptide AAN46801.1 Arabidopsis thaliana 99 polypeptide XP_482841.1 Oryza sativa 100 polypeptide AAS79671.1 Brassica juncea 101 polypeptide AAS79670.1 Brassica juncea 102 polypeptide AAS79669.1 Brassica juncea 103 polypeptide BAB02870.1 Arabidopsis thaliana 104 polypeptide AAM70569.1 Arabidopsis thaliana 105 polypeptide BAC42751.1 Arabidopsis thaliana 106 polypeptide AAK38667.1 | AF353615_1 Nicotiana tabacum 107 polypeptide AAK18620.1 | AF352732_1 Nicotiana tabacum 108 polypeptide AAP85548.1 Glycine max 109 polypeptide AAM48129.1 | AF506366_1 Nicotiana tabacum 110 polypeptide AAM61251.1 Arabidopsis thaliana 111 polypeptide AAP79441.1 Oryza sativa 112 polypeptide AAL91148.1 Arabidopsis thaliana 113 polypeptide XP_482840.1 Oryza sativa 114 polypeptide AAL16126.1 | AF428294_1 Arabidopsis thaliana 115 polypeptide AAC39483.1 Nicotiana tabacum 116 polypeptide AAM70582.1 Arabidopsis thaliana 117 polypeptide AAC24195.1 Nicotiana tabacum 118 polypeptide AAB40608.1 Nicotiana tabacum 119 polypeptide AAA93132.1 Arabidopsis thaliana 120 polypeptide A48767 Petunia × hybrida 121 polypeptide AAL83983.1 Oryza sativa 122 polypeptide CAA56812.1 Lycopersicon esculentum 123 polypeptide XP_46254.1 Oryza sativa 124 polypeptide AAM47304.1 | AF377946_6 Oryza sativa 125 polypeptide BAB32871.1 Oryza sativa 126 polypeptide AAT77842.1 Oryza sativa 127 polypeptide AAP46640.1 Hordeum vulgare 

1. A method for producing a plant with altered seed yield, the method comprising transformation of a plant with: a) a polynucleotide encoding of a polypeptide with the amino acid sequence of SEQ ID NO:1 or a variant of the polypeptide, wherein the variant is capable of modulating seed yield in a plant; b) a polynucleotide comprising a fragment, of at least 15 nucleotides in length, of the polynucleotide of a), or c) a polynucleotide comprising a compliment, of at least 15 nucleotides in length, of the polynucleotide of a).
 2. The method of claim 1 in which the variant has at least 70% sequence identity to a polypeptide with the amino acid sequence of SEQ ID NO:
 1. 3. The method of claim 1 or claim 2 in which the variant is derived from a plant species and comprises the amino acid sequence of SEQ ID NO:
 32. 4. The method of any one of claims 1 to 3 in which the variant is derived from a monocotyledonous species and comprises the amino acid sequence of SEQ ID NO:
 33. 5. The method of any one of claims 1 to 3 in which the variant comprises an amino acid sequence selected from any one of SEQ ID NO: 2-31.
 6. The method of any one of claims 1 to 5 in which the variant is a glutamate decarboxylase.
 7. The method of claim 1 in which the polynucleotide of a) encodes a polypeptide with the amino acid sequence of SEQ ID NO:
 1. 8. A method of producing a plant with altered seed yield, the method comprising transformation of a plant cell or plant with: a) a polynucleotide comprising the nucleotide sequence of SEQ ID NO: 34, or a variant thereof, wherein the variant encodes a polypeptide capable of modulating seed yield in a plant; b) a polynucleotide comprising a fragment, of at least 15 nucleotides in length, of the polynucleotide of a), or c) a polynucleotide comprising a complement, of at least 15 nucleotides in length, of the polynucleotide of a).
 9. The method of claim 8 in which the variant has at least 70% sequence identity to SEQ ID NO:
 34. 10. The method of claim 8 in which the variant has at least 70% sequence identity to the coding sequence of SEQ ID NO:
 34. 11. The method of claim 8 in which the variant comprises the sequence of any one of SEQ ID NO: 35 to
 65. 12. The method of claim 8 in which the variant comprises the coding sequence of any one of SEQ ID NO: 35 to
 65. 13. The method of any one of claims 8 to 12 in which the polypeptide is a glutamate decarboxylase.
 14. The method of claim 8 in which the polynucleotide of a) comprises the sequence of SEQ ID NO:
 34. 15. The method of claim 8 in which the polynucleotide of a) comprises the coding sequence of SEQ ID NO:
 34. 16. The method of any one of claims 1 to 15 in which the plant produced has increased seed yield relative to a suitable control plant.
 17. A plant cell or plant produced by a method of any one of claims 1 to
 16. 18. An isolated polynucleotide encoding a polypeptide with at least 75% sequence identity to the amino acid sequence of SEQ ID NO: 1, wherein the polynucleotide encodes a polypeptide capable of modulating seed yield in a plant.
 19. The isolated polynucleotide of claim 18 wherein the polypeptide is a glutamate decarboxylase.
 20. The isolated polynucleotide of claim 18 comprising the sequence of SEQ ID NO:
 34. 21. The isolated polynucleotide of claim 18 comprising coding sequence of SEQ ID NO:
 34. 22. An isolated polypeptide having at least 83% sequence identity to the amino acid sequence of SEQ ID NO: 1, wherein the polypeptide is capable of modulating seed yield in a plant.
 23. The isolated polypeptide of claim 22, wherein the polypeptide is a glutamate decarboxylase.
 24. The isolated polypeptide of claim 22 comprising the amino acid sequence of SEQ ID NO:
 1. 25. A genetic construct which comprises a polynucleotide of any one of claims 18 to
 21. 26. A genetic construct including a polynucleotide consisting of at least one of: a) a fragment, of at least 15 nucleotides in length, of a polynucleotide of any one of claims 18 to 21; b) a complement, of at least 15 nucleotides in length, of the polynucleotide of any one of claims 18 to 21; or c) a sequence, of at least 15 nucleotides in length, capable of hybridising to the polynucleotide of any one of claims 18 to
 21. 27. The genetic construct of claim 26 comprising a promoter sequence operably linked to the polynucleotide.
 28. The genetic construct of claim 26 or 27 comprising a terminator sequence operably linked to the polynucleotide.
 29. A host cell genetically modified to express a polynucleotide of any one of claims 18 to 21, or a polypeptide of any one of claims 22 to
 24. 30. A host cell comprising a genetic construct any one of claims 25 to
 28. 31. A plant cell genetically modified to express a polynucleotide of any one of claims 18 to 21, or a polypeptide of any one of claim 22 or
 24. 32. A plant cell which comprises a genetic construct any one of claims 25 to
 28. 33. A plant which comprises a plant cell of claim 31 or
 32. 34. A method for selecting a plant with altered seed yield relative to suitable control plant, the method comprising testing of a plant for altered expression of a polynucleotide of any one of claims 18 to
 21. 35. A method for selecting a plant with altered seed yield relative to a suitable control plant, the method comprising testing of a plant for altered expression of a polypeptide of claims 22 to
 24. 36. A group of plants selected by the method of claim 34 or
 35. 37. An antibody raised against a polypeptide of any one of claims 22 to
 24. 